JVC RS40 3D PJ

[Anonymous]

Anyone calibrate one yet? I plan on calibrating a friends this weekend to see if there are any issues.

Topic

[Gregg Loewen]

ignore the offsets and use the gamma controls to adjust the dark side of the gray scale and also the gamma.

[Anonymous]

@Gregg Loewen 3011 wrote:

ignore the offsets and use the gamma controls to adjust the dark side of the gray scale and also the gamma.

Hi Gregg. In the end that’s what I’ve practically ended up doing. I got things as close as I could with the offsets and then tweaked problem areas with the gamma. Took me a while to work out that it was ok to do this though! Any idea what’s up with these X3s (Dean’s and the one I was working on?)

[Gregg Loewen]

nothing wrong…basically it is how all the JVCs work since the RS-2 PJ. dont use the offsets.

Use the gain controls to nail 100% stimulus (after ensuring that you are not clipping), then use the gamma controls to smooth the gray scale.

[Anonymous]

Really? Wow, that comes as a huge surprise since I’ve always used the offsets to calibrate my own RS20. No problems achieving a lovely flat greyscale this way either. So, I mean, what’s up with the offsets? Should I recalibrate by tweaking the gamma only if I’m already getting a flat greyscale this way? (I should explain that I’ve always subtracted with the offsets – never raised them above 0 as I read this affected the black level.)

[Anonymous]

Chaps – I’ve been “playing” with caibrating our JVC DLAX7 pj, also getting poor light output, is everyone driving the lamp on full power/aperture wide open?
Have a black ceiling/black fabric walls and 7ft wide screen.

Cheers

[Anonymous]

@Martin Redwood 3027 wrote:

Chaps – I’ve been “playing” with caibrating our JVC DLAX7 pj, also getting poor light output, is everyone driving the lamp on full power/aperture wide open?
Have a black ceiling/black fabric walls and 7ft wide screen.

Cheers

Hi, the X3 I spent 2 days with last week had a light level that would concern me. With only 600 hours on the bulb and with the aperture completely open in high lamp mode I could only get 13fl. My HD750 at home has 900 hours on the clock and with high lamp and aperture at -5 I am getting over 14fl. These are both in well treated rooms with black walls, ceilings etc.

[Anonymous]

@Julian Scott 3029 wrote:

Hi, the X3 I spent 2 days with last week had a light level that would concern me. With only 600 hours on the bulb and with the aperture completely open in high lamp mode I could only get 13fl. My HD750 at home has 900 hours on the clock and with high lamp and aperture at -5 I am getting over 14fl. These are both in well treated rooms with black walls, ceilings etc.

Pretty much everyone on AVS is complaining about the same thing…. check out the RS50 thread…. people are mad about it.

[Anonymous]

Actually, on the forums, people are abandoning the RS50 and 60 in favor of the 40 because the 40 is considerably brighter. I got 45 fL from an RS60 (same as the 50, but it uses only the best of the subassemblies used to make the 50… and it costs an additional $4000). But the only way to get that much light is to set Color Pallet to OFF which gives you completely uncorrected light from the projector… which gave a HUGE plus-cyan error. Any mode that’s reasonably close to Rec 709 would produce about 17 fL with a new lamp and 13 fL with 600 hours on a 1.0 gain screen that’s only 6 feet wide. I can’t even imagine how weak it would be on a 9 or 10 foot screen. You’d need a lot of gain (and all the problems that go with that) for any fairly large screen.

[Anonymous]

Finished playing – got 13.7Fl, decent grayscale but woeful gamma. I tried the 2.6 curve with D correction and can’t do better than 1.8! I guess I’m doing something wrong..

[Gregg Loewen]

Hi Martin, I have also responded to your email.

Set 100% by the RGB gains, select gamma 2.6 with custom gamma. Then get the rest of the gray scale to d65 by using the rgb gamma controls. Also use the White gamma control to pull the rest of the gamma curve to 2.35.

Remember to keep rechecking 100% and adjusting the RGB gains to keep at D65.

[Anonymous]

I did one today. I got about 13ft/L on a 100in screen. Calibrated as suggested. Was ok till 50%, then gamma started dropping slowly. Used white gamma control to pull down the gamma from 50-90% but at 80 and 90% had to pull it down a lot as gamma was about 1.7-1.9 at 80 and 90. Then saw coloration in the above white. I guess I need to revisit the client as I was not too happy and he had other things to do. This was after a 3hr session….

Not sure what the trick is.

[Anonymous]

To those that has successfully calibrated the x3, did u use user or film mode to begin with? I am scheduled to revisit the client and would need to restart. I recall the user and the film both were close. Another question is 3d calibration on the x3, did u use the 3d mode?

[Anonymous]

I haven’t worked on a “40” but have spent a lot of time with the 50/60 (have a 60 here now). So this applies to the 50/60… not sure if it also applies to the 40.

There is a problem with 3D mode that causes “electric” reds and oranges that don’t appear in grayscale or CMS measurements. If you view content after the calibration that doesn’t have the right shades of red or orange so that you can SEE the problem, you could easily miss it. It might be fixable with an adjustment (and measurements) at 95% stimulus, but you may not be able to fix it with the controls in the 50/60. To get around the problem, I used Cinema mode for 3D, setting it to High lamp mode. High lamp mode is absolutely needed for the 50/60 in 3D mode… with a brand new lamp you may think 3D is bright enough that High is not needed, but after the lamp gets to 300-400 hours, you DEFINITELY begin to feel like 3D is too dark in Normal lamp mode. You may or may not need High lamp with the 40… the 40 makes more light than the 50/60 by quite a bit.

I think the lesson here is to measure 20 or 21 points when you think you are done to make sure you haven’t missed a narrow-band problem that is EASILY visible in the final images. I’ve already seen another RS60 that was calibrated (by someone else) for 3D using 3D mode and it had the SAME “electric” red & orange problem mine had (firmware is 1.5 I think) for 3D content. This shows up really well in some of the costumes in the 3D Cirque du Soleil disc that came out recently. Properly calibrated, the “electric” reds and oranges appear “normal” which is bright in these costumes, but not so bright that they appear impossible without their own power source!

[Anonymous]

@Doug Blackburn 3148 wrote:

I haven’t worked on a “40” but have spent a lot of time with the 50/60 (have a 60 here now). So this applies to the 50/60… not sure if it also applies to the 40.

There is a problem with 3D mode that causes “electric” reds and oranges that don’t appear in grayscale or CMS measurements. If you view content after the calibration that doesn’t have the right shades of red or orange so that you can SEE the problem, you could easily miss it. It might be fixable with an adjustment (and measurements) at 95% stimulus, but you may not be able to fix it with the controls in the 50/60. To get around the problem, I used Cinema mode for 3D, setting it to High lamp mode. High lamp mode is absolutely needed for the 50/60 in 3D mode… with a brand new lamp you may think 3D is bright enough that High is not needed, but after the lamp gets to 300-400 hours, you DEFINITELY begin to feel like 3D is too dark in Normal lamp mode. You may or may not need High lamp with the 40… the 40 makes more light than the 50/60 by quite a bit.

I think the lesson here is to measure 20 or 21 points when you think you are done to make sure you haven’t missed a narrow-band problem that is EASILY visible in the final images. I’ve already seen another RS60 that was calibrated (by someone else) for 3D using 3D mode and it had the SAME “electric” red & orange problem mine had (firmware is 1.5 I think) for 3D content. This shows up really well in some of the costumes in the 3D Cirque du Soleil disc that came out recently. Properly calibrated, the “electric” reds and oranges appear “normal” which is bright in these costumes, but not so bright that they appear impossible without their own power source!

Thanks for the input Doug.

I calibrated a 40 today. Got decent gamma tracking by using Gregg’s method of using gains for the 100% and custom gamma for the rest. Set gamma using the 50,60,50,40,50,60,40 etc… method, then corrected greyscale and touched up gamma. This way there is not major issues with gamma tracking. I did notice that at 25% there was a spike of red that was visible and the meter was seeing it as well. However, since there is no way to adjust 25% I left it at that. I got about 14ft/L with normal lamp settings on a 110in screen.

For 3D, using 3D mode, and high lamp I got about 3ft/L (thru the glasses). Post calibration I got about 2 ft/L. No 10point gamma in 3D so the low end was clearly red tinted below 30%, from 30-100% it was pretty decent. Still, it looked good. Not sure how long though, since its so dim.

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